How to manage a patient with hyperkalemia already on Lokelma (sodium zirconium cyclosilicate) and Kayexalate (sodium polystyrene sulfonate)?

Managing a Patient on Both Lokelma and Kayexalate for Hyperkalemia

When a patient is already on both Lokelma (sodium zirconium cyclosilicate) and Kayexalate (sodium polystyrene sulfonate), discontinue Kayexalate and continue with Lokelma alone as the preferred potassium binder due to its superior safety profile and efficacy.

Assessment of Current Therapy

• Concurrent use of two potassium binders is unnecessary and potentially harmful, as each agent alone can effectively manage hyperkalemia when properly dosed 1
• Kayexalate (sodium polystyrene sulfonate) has significant safety concerns including risk of severe gastrointestinal side effects such as bowel necrosis, particularly with prolonged use 1, 2
• Lokelma (sodium zirconium cyclosilicate) has a more favorable safety profile, faster onset of action (1 hour vs. several hours for Kayexalate), and higher selectivity for potassium 1, 3

Recommended Management Algorithm

1. Discontinue Kayexalate immediately

   • Chronic use of SPS (Kayexalate) should be avoided due to risk of severe gastrointestinal side effects 1, 2
   • SPS has never undergone rigorous testing in placebo-controlled clinical trials to prove its efficacy and safety 1

2. Continue and optimize Lokelma dosing

   • For maintenance therapy, Lokelma can be dosed from 5g every other day up to 15g once daily based on serum potassium levels 3
   • Monitor serum potassium closely after discontinuing Kayexalate to ensure adequate control with Lokelma alone 1

3. Evaluate and address underlying causes of hyperkalemia

   • Review patient's diet, supplements, salt substitutes, and medications that may contribute to hyperkalemia 1
   • Consider adding or optimizing loop or thiazide diuretics if appropriate to increase potassium excretion 1

4. Assess RAAS inhibitor therapy

   • For K+ levels >5.0–<6.5 mEq/L on RAAS inhibitors, maintain therapy while using Lokelma 1
   • For K+ levels >6.5 mEq/L, discontinue/reduce RAAS inhibitor therapy temporarily 1
   • Once K+ levels are <5.0 mEq/L, consider reintroduction of RAAS inhibitors at lower doses with close monitoring 4

Medication Administration Considerations

• Lokelma should be administered at least 2 hours before or after other oral medications due to potential drug interactions 3
• Lokelma can increase systemic exposure to weak acids (like furosemide and atorvastatin) and decrease exposure to weak bases (like dabigatran) 3
• Unlike Kayexalate, Lokelma does not require sorbitol for administration, reducing gastrointestinal side effects 1

Monitoring Recommendations

• Check serum potassium within 1 week of changing potassium binder therapy 1
• Monitor for hypokalemia, which occurred in 10-11% of patients on higher doses (10-15g) of Lokelma in clinical trials 5
• Watch for edema, which is more common with higher doses of Lokelma (14% incidence with 15g daily) 1
• Monitor serum magnesium, as both agents can cause hypomagnesemia 1

Special Considerations

• If the patient has heart failure, severe hypertension, or marked edema, be aware that both medications contain sodium (Lokelma: 400mg per 5g dose; Kayexalate: 1500mg per 15g dose) 1
• For patients with chronic kidney disease, Lokelma is preferred as it has been specifically studied in this population 1, 6
• If cost is a concern, consider discussing with the patient's insurance provider, as newer potassium binders like Lokelma may be more expensive than Kayexalate 1